Abstract: Various catastrophes, such as earthquakes, tsunamis, and floods, not only result in huge casualties and property losses, but also make the government not run basic functions for social management and disaster relief, leading to an unprecedented disorder. Therefore, it is an important part of disaster emergency management for a government to ensure its basic functions continuous. The core content of a government continuity of operations (COOP) is to avoid essential functions being interrupted, meanwhile identification of essential functions lays the foundation for COOP. According to four basic functions of our government, based on organizing disaster relief effectively and maintaining basic social orders, specific functions of government COOP during catastrophe scenario are constructed. Judging by importance of functions to the organizational mission, consequences of lacking performance, and time-criticality, essential functions of government under catastrophe scenarios are divided, and the priority of essential functions are determined by using AHP.